PR #12982: fix(ui-tui): prevent stickyScroll re-activation after manual scroll-up

• Repository: NousResearch/hermes-agent
• Author: MestreY0d4-Uninter
• State: open | merged: False
• Link: https://github.com/NousResearch/hermes-agent/pull/12982

Description (problem / solution / changelog)

Summary

Fixes #12884 - Prevents aggressive stickyScroll re-activation when user manually scrolls up to view previous content.

Problem

The follow-on-scroll mechanism in render-node-to-output.ts restores stickyScroll=true when:

• User is positionally at bottom (scrollTopBeforeFollow >= prevMaxScroll)
• stickyScroll === false (explicitly broken by scrollTo/scrollBy)

However, this was too aggressive - streaming content would re-activate sticky mode immediately after user scrolls up, fighting user intent.

Solution

Add recentScrollUpTime tracking to prevent re-activation:

1. DOMElement type (dom.ts): Add recentScrollUpTime?: number property
2. scrollBy() (ScrollBox.tsx): Set timestamp when dy < 0 (scroll-up)
3. scrollToBottom() (ScrollBox.tsx): Clear timestamp (explicit go-to-bottom)
4. follow-on-scroll (render-node-to-output.ts): Check recentScrollUpTime before restoring sticky (500ms cooldown)

Testing

• All 92 existing tests pass
• TypeScript compiles cleanly
• Build succeeds

Files Changed

• ui-tui/packages/hermes-ink/src/ink/dom.ts - Add recentScrollUpTime property
• ui-tui/packages/hermes-ink/src/ink/components/ScrollBox.tsx - Track scroll-up timestamp
• ui-tui/packages/hermes-ink/src/ink/render-node-to-output.ts - Check timestamp before restoring sticky

Changed files

• ui-tui/packages/hermes-ink/src/ink/components/ScrollBox.tsx (modified, +26/-20)
• ui-tui/packages/hermes-ink/src/ink/dom.ts (modified, +4/-0)
• ui-tui/packages/hermes-ink/src/ink/render-node-to-output.ts (modified, +12/-8)